The Home Machinist!

You are going to have to build a frame to support it.

Most Bridgeport's type mills have the belt system between two bearings...and there is a frame around and above the pulleys onto which this type of unit can be mounted.

Most mill drills have the belts as the upper most part of the machine with no frame above the pulley to which you can mount a power drawbar.

Yes...it can be done but is going to be a lot of work

I use a right angle impact driver along with a right angle drill adaptor with a 3/4" socket. It was cheap and works, plus you can use the impact driver for other work, as needed. The trigger is up against the mill head, so a slight pressure activates it You can hold the driver near its bottom.

THAT's a creative solution!

I've found several inexpensive power drawbar devices online.
But decided it is good rehab exercise for my rebuilt shoulder to manually do the job.
RussN

I have owned my share of BP mills but the Tree mill with the snap change was superior. For a home shop I have a spin handle to load and unload the collet. Speeds things up but if your trying to make money, the power drawbar is a must. Like the other post said " lot a sugar for a dime " if only a hobby shop.

When I first bought my Mill 25 years or so ago, I also purchased an air butterfly kit similar to the OPs. It worked great for many years until one of the slider posts broke off. It was made of engineered plastic, tough however still weak for the intended purchase. I never fixed it or bought another. I actually removed the bracket last week as I was working on the mill anyways.

Out of curiosity I looked on Ebay to see what is available today. The lower cost unit I saw was made out of steel and aluminum, a much needed improvement.